Which of the following pairs have identical bond order?

Options

A. `F_(2) and O_(2)^(2-)`
B. `N_(2) and CO_(2)`
C. `O_(2) and O_(2)^(-)`
D. `N_(2) and N_(2)^(+)`

Explanation

To determine which pairs of molecules have identical bond orders, we need to calculate the total number of electrons in each molecule. The bond order can be determined by the number of electrons present; if two molecules have the same number of electrons, they will have identical bond orders.

### Step-by-Step Solution:

1. **Identify the pairs of molecules**: The question provides pairs of molecules to analyze for identical bond orders. The pairs are:
- (i) F2 and O2^2-
- (ii) N2 and CO2
- (iii) O2 and O2^-
- (iv) N2 and N2^+

2. **Calculate the total number of electrons for each molecule in the pairs**:
- **Pair (i): F2 and O2^2-**
- F2: Each fluorine (F) has 9 electrons. Therefore, F2 has 2 × 9 = 18 electrons.
- O2^2-: Each oxygen (O) has 8 electrons. Therefore, O2 has 2 × 8 = 16 electrons. Adding 2 extra electrons for the 2- charge gives us 16 + 2 = 18 electrons.
- **Conclusion**: F2 and O2^2- both have 18 electrons.

- **Pair (ii): N2 and CO2**
- N2: Each nitrogen (N) has 7 electrons. Therefore, N2 has 2 × 7 = 14 electrons.
- CO2: Carbon (C) has 6 electrons and each oxygen (O) has 8 electrons. Therefore, CO2 has 6 + 2 × 8 = 22 electrons.
- **Conclusion**: N2 has 14 electrons and CO2 has 22 electrons; they do not have the same number of electrons.

- **Pair (iii): O2 and O2^-**
- O2: Each oxygen has 8 electrons. Therefore, O2 has 2 × 8 = 16 electrons.
- O2^-: O2 has 16 electrons, and adding 1 extra electron for the -1 charge gives us 16 + 1 = 17 electrons.
- **Conclusion**: O2 has 16 electrons and O2^- has 17 electrons; they do not have the same number of electrons.

- **Pair (iv): N2 and N2^+**
- N2: Each nitrogen has 7 electrons. Therefore, N2 has 2 × 7 = 14 electrons.
- N2^+: N2 has 14 electrons, and removing 1 electron for the +1 charge gives us 14 - 1 = 13 electrons.
- **Conclusion**: N2 has 14 electrons and N2^+ has 13 electrons; they do not have the same number of electrons.

3. **Final Conclusion**: The only pair that has identical bond order is F2 and O2^2- since both have 18 electrons.

### Answer:
The pair that has identical bond order is **F2 and O2^2-**.